Transfer cases are a common method of transferring power to more than one set of wheels in a motor vehicle. Devices such as transfer cases often have the ability to operate at more than one gear ratio. Typically a 1:1 gear ratio is used, and less often a reduced gear ratio, which can range from 1.5:1 to 4:1, is also used to generate more torque. For the transfer case to provide a transfer of power to more than one set of wheels in the vehicle, it is common practice for various types of synchronizers to be used to engage the gears in the transfer case providing the different gear ratios. These synchronizers can provide a smooth power transition with minimal effort.
Because typical driving conditions do not mandate the use of the reduced speed, high-torque gearset in the transfer case, most owners of vehicle equipped with four-wheel-drive do not ever use this function of the transfer case.